The invention relates to a ball valve comprising a one piece housing opposed bearing points for supporting a ball which is inserted into the housing from outside thereof.
In the case of ball valves of the generic type provided with a one-piece housing, the ball is inserted into the housing via a fluid opening. In order to be able to rotate the ball accommodated in the housing, which can be equated with the operation of the ball valve, in the normal case a pin is provided which is connected to the ball in a force-fitting and/or positive manner, is led to the outside through the wall of the housing and is provided with an operating lever at the end. The pin connected to the ball simultaneously acts as a bearing pin which supports the ball on one side. In order to seal off the ball with respect to the fluid openings (inlets and outlets) of the ball valve, provision is made for screw-in elements of the hollow cylindrical design, whose end faces are provided with annular spherical seals. These screw-in elements are screwed into internal threads in the fluid openings, so that the spherical seals rest snugly on the ball. The disadvantage with ball valves designed this way is that the seals also have to absorb lateral forces from the ball, since the ball has the tendency to escape laterally when the fluid openings are closed, as a result of the prevailing fluid pressure. Since the ball is mounted only on one side and the spherical seals, because of their principle, have to be resilient, these lateral forces cause lateral movements of the ball, which may lead to leaks in the valve. In addition, such seals are subject to excessively high wear. Moreover, ball valves of this type are suitable only for comparatively low fluid pressures.
It is therefore an object of the present invention to improve a ball valve of the type described above in such a way that the ball valve effects reliable sealing with long-term stability and, moreover, is simple and cost-effective to produce.